The efficient transportation of petroleum products (crude oil, gasoline, chemicals, natural gas) is critical to meeting the world's energy demands. Pipelines, rail cars, tankers, ships, and trucks all work in harmony in the transportation network to deliver energy to consumers. The most critical component of this network is the pipeline. North America alone depends on over 185,000 miles of liquid petroleum pipelines, 320,000 miles of gas transmission pipelines, and more than two million miles of gas distribution pipelines. Petroleum products will spend the majority of their transportation time in the pipeline.
Ideally, the pipeline is constantly transporting petroleum products with little or no downtime. However, in certain circumstances, transportation may stop for repair or maintenance purposes to the pipeline or distribution equipment. During the oil pipeline repair or maintenance, it is often required to remove a blind flange at the end of an oil pipe. To ensure a technician's safety and environmental safety, prior to the removal of the blind flange, it is critical that there is no significant amount of oil in the pipeline and there is no pressure build-up behind the flange. If there is any remaining oil or higher than atmospheric pressure inside the pipeline, the oil should be removed and the pressure should be released before removing the flange. However, currently there is no apparatus, safe and closed process, or method that can measure the pressure, remove oil, and release high pressure gases without removing the flange. Pipeline operators normally complete the check by loosening a few bolts/studs holding the blind flange in place and wait to see if oil leaks out. This is risky from both an environmental and safety perspective. Fluids in the pipeline, such as oil, may be sprayed onto personnel or nearby objects, and cannot be stopped except for quickly tightening the flange. Additionally, using this method can give a false indication that the product is continually filling what should be a void space.
U.S. Pat. No. 4,082,002 discloses an apparatus for mounting a pressure gauge or pressure transducer for measuring the pressure in a high pressure manifold or line. Some commercially available diaphragm flange devices can also be used to measure the pressure behind a flange in a pressure manifold or line. However, there is no known disclosure for an apparatus that can both measure pressure within a pipeline as well as remove fluid such as oil from a pipeline in a closed process without removing the flange. In addition, the apparatus disclosed in the prior art is not suitable for oil pipelines that are buried in the soil for extended period of time because the complicated underground soil conditions may damage the pressure measuring devices due to moisture level and other potential corrosive conditions.